I won WW3 in as the European Federation.
I was invaded by both America and Russia and America. But I pushed the Russians back then I took Moscow and so Russia fell. Then I drove the Americans out of Europe in the west, then had complete control of the entire continent of Europe, then crossed the Atlantic onto their land and marched towards Washington. Before I could reach the capital America surrendered.
When fighting the Americans in the last series of battles I used Blitzkreig tactics. Spawning with many tanks and infantry fighting vehicles, racing across the map while taking out enemies, having infantry capture uplinks behind the spearhead, and storming and overrunning their spawn point with the help of gunship reinforcements and sometimes mobile artillery. Easy victories.